OHS Canada Magazine

Dressed for Fire

February 8, 2017
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By Jeff Cottrill

For many people, getting dressed for work does not mean donning a shirt and a tie or a blouse and a jacket. The proper attire for employees who work with open flames, electrical equipment, flammable materials and other potential fire or explosion hazards is fire-retardant or flame-resistant (FR) apparel that protects against burns.

Not to be confused with the protective uniforms that firefighters wear, FR apparel is designed specifically to protect against burn injuries from sudden, unexpected flash fires or electric-arc flashes. Fire-retardant apparel comes in the form of shirts, jackets, pants, overalls, hoods with face shields, outdoor outerwear and full-body coveralls.

There are also high-visibility options for workers who need to be seen by others, including those who operate around streets or highway traffic, and even “breathable” gear that keeps water and other liquids out in bad weather or wet environments. Some FR clothing is made with antimicrobial properties to control odours as well.

The primary markets for FR apparel are the utilities and oil and gas sectors. Chemical plants also find such protective clothing useful, as do industries that manufacture flammable products, including lumber and plastics.

Hazard check

As with any personal protective equipment (PPE) or other products designed for worker safety, it is important that a company assess a work area’s prevalent hazards before deciding which kind of FR apparel to purchase. Mark Saner, technical manager with Workrite, an Oxnard, California-based company that manufactures and sells FR apparel, identifies two main categories of fire hazards present in many industries: hydrocarbon flash fires and electric arcs. The former are sudden, short fires that occur when air mixes with flammable substances, while the latter are quick flashes of electric current that leave the intended path and travel through the air from one conductor to another or to the ground.

Fire-resistant garments that protect against electric-arc flashes are called arc-rated garments, made out of fabrics tested to determine their level of protection against thermal exposures from electric-arc flashes. “You have got electricians working on those high-voltage electrical panels, and they have to be protected in case there is an accidental arc flash that explodes,” Saner says.

Hydrocarbon flashes and electric arcs are not the only causes of fires present in industrial work. “Combustible dust is another one,” Saner points out. “Whether it is plastics or wood products or agricultural products, those can create combustible dust that could explode into a flash that could ignite clothing.” Molten-metal splashes are another risk against which some FR apparel is designed to protect.

Andrew Wirts, sales and marketing director with Washington, Indiana rainwear manufacturer NASCO, says it is important to understand the differences presented by various flame-resistant characteristics. “You can’t just paint all FR clothing with a single brush. For example, there are products that perform very well against an electric-arc flash, but do very poorly against a hydrocarbon flash fire.”

Fortunately, Wirts says, many FR products can handle both types of flashes. That said, workers should still familiarize themselves with safe-work practices that minimize the risks in their environments, so that “apparel becomes not the first line of defence. It’s sort of the last line of defence.”

Pick and choose

In view of the sheer variety of FR clothing available on the market, employers should bear in mind certain factors, such as the manufacturer’s selection of fabrics and styles, the apparel’s quality and price, the quality-control process used and the manufacturer’s ability to provide technical expertise and information to maximize the protective gear’s effectiveness.

Fire-resistant garments are so essential to certain sectors that many companies in North America focus exclusively on manufacturing and selling them. The spectrum of FR gear available is so diverse that some companies specialize exclusively in rainwear, or FR apparel with waterproof characteristics. “Not only is it the weather that they are trying to protect against, but it might be chemicals or sludge or cleaning solutions or things like that, that also have a flammable nature to them,” says Wirts of NASCO, which sells only rainwear.

Comfort is key when choosing the proper FR gear. The proper fit of the garment can affect the protective level as well. As well, the fabric from which an FR garment is made can influence its cost.

“The largest percentage of the component in the garment itself is the fabric,” Saner notes. Some apparel is more expensive, because the fabric is tough enough to withstand a harsh work environment full of hard physical activity. “In some extremely rough industries, garments can wear out in a matter of months, so you want to make sure you get your money’s worth out of those garments,” he suggests.

Another influencing factor on the price tag is how the FR apparel was made. High-quality clothing with higher stitch counts, extra reinforcements, extra materials and stronger sewing thread tends to cost more.

How can one determine if a piece of FR clothing offers effective protection? That is a tricky question, Saner says. “You really don’t know if it is still flame-resistant unless you put a flame to it, which obviously is going to ruin the garment.” As well, test results of the destroyed garment do not necessarily reflect the effectiveness of the other garments. Saner recommends choosing apparel from manufacturers who guarantee that the protection will last as long as the apparel does.

Layer upon layer

Just because one is wearing FR gear does not mean that one is completely protected. Wirts cites the common misconception that wearing FR apparel underneath regular outer garments — or over a layer of other clothing — will protect a worker.

“Non-FR layers can ignite and burn under an FR layer,” he explains. “Conversely, an FR or non-FR layer as the outermost layer can be an ignition source for an FR layer underneath.” If a non-FR outer layer of clothing is made of a melting or dripping material, it “can actually melt through the FR layer and create burns that would not have otherwise been there.”

Any additional PPE that one wears should not hinder or cancel out a garment’s ability to resist flame threats. For example, many hard hats are now designed with higher melting thresholds. But workers have been injured for wearing synthetic or nylon protective gear that, while offering protection in other ways, could not stop burns.

If layering is needed in a cold environment, fire-retardant apparel should be worn over non-melting fabrics or other FR material, such as a Nomex coverall over an FR shirt. This offers extra protection and provides thermal insulation through air gaps, which increase the overall protective ability of the clothing. Ensuring that a piece of FR clothing provides a good fit is also important.

FR gear is relatively simple to maintain. The most important thing is to keep it clean. The same applies to rainwear. Ransome cites a scenario in which a worker wearing a protective rain suit operates in a greasy environment, but fails to keep the garment clean and free from oil. Those things could add to the burn injury in the event of an incident, he cautions. It is also worth noting that some FR clothing is made of inherently flame-resistant fibres like Nomex, Kevlar or modacrylics, while other clothing consists of flammable fabrics, such as cotton, treated with a flame-resistant chemical.

While manufacturers use treatments that are not easily washed out or worn out, lack of proper care and maintenance can compromise the protective function of FR clothing. “If you pour bleach on them or things like that, then they can actually start to degrade the protective capabilities,” Saner says. As such, many manufacturers advise against using bleach and peroxides when laundering such apparel.

Regarding storage, Saner recommends keeping FR apparel dry and shielding it away from the sun and high temperatures. “You don’t want mould and mildews,” he says. “And you don’t want ultraviolet [rays], because it can start to degrade, fade the colours and start to weaken the fibres.”

With proper maintenance, a high-quality FR garment should last five years or longer, while less expensive gear has a lifespan of about a year and a half.

Jeff Cottrill is the editor of Canadian Occupational Health and Safety News.

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